ARDS肺复张的测定

急性呼吸窘迫综合征肺复张的测定与应用,邱海波东南大学附属中大医院东南大学急诊与危重病研究所,内容提要,ARDS病理生理ARDS肺复张容积测定P-V曲线法等压法CT法：Gattinonis vs RoubysARDS肺复张测定应用明确肺不张的分布与特点评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用指导PEEP选择,Lung volume decreased markedly (TLC, VC, TV, FRC) -alveolar edema -pulmonary surfactant -Interstitial pumonary edema depress brochiole and induce spasmCompliance reduced significantlyVentilation/perfusion mismatch -intrapulmonary shunt and dead space like effects,ARDS病理生理特点,ARDS病理生理,CT scan70-80% 的肺野呈现高密度区分布：下垂部位(dependent field)提示：参与通气肺泡明显减少(20-30%) 肺损伤具有不均一性,肺容积减少Small lung Baby Lung,ARDS病理生理,A and C finding in the acute or exudative phase,B and DFinding in the fibrosing-alveolitis phase,ARDS病理生理,肺容积/顺应性明显降低,ARDS病理生理,Reduced range of volume excursion: Low complianceFlattening at low and high volumes: Lower and upper inflection pointsBigatello: Br J Anaest 1996,Volume,Pressure,NORMAL,ARDS,顺应性曲线明显右下移位,肺顺应性明显降低,ARDS病理生理,Upper and Lower Inflection Points,Lower呼气末肺泡塌陷吸气早期肺泡再开放Upper吸气末肺泡顺应性明显降低，肺泡过度膨胀,ARDS病理生理,Volume,Pressure,Lower Inflection Point,Upper Inflection Point,通气/血流失调,肺泡塌陷：ARDS重力依赖区，炎症或不张区生理性低氧缩血管反应：障碍,ARDS病理生理,Imagine the Hardness to Blow up a Ballon .,easy,hard,spatial & elastic limitations,Laplacian Law,It needs higher initial pressures to overcome the surface tension to open up a bubble to wider diameters!,ARDS病理生理,Sustain inflation Sigh小潮气量通气PHC, 避免肺泡过度膨胀最佳PEEP避免剪切力(Shear force)性损害,Volume,Pressure,肺开放与保护性通气策略的基本内容,ARDS病理生理,Lung volume decreased markedly,Atelectrauma,Keep the lung open,Open the lung,Prevent volutrauma,SI and Sigh,PEEP,ARDS病理生理,内容提要,ARDS病理生理ARDS肺复张容积测定P-V曲线法等压法CT法：Gattinonis vs RoubysARDS肺复张测定应用明确肺不张的分布与特点评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用指导PEEP选择,PV曲线法,Step 1: 测量PEEP所致的FRC(吸气末撤掉PEEP并延长呼气时间) FRCVE(ZEEP) VE(PEEP),肺复张容积测定,PV曲线法,Step 2: 分别描计ZEEP和PEEP的PV曲线 Step 3: 肺复张容积：RV= V20(PEEP) + FRC V20(ZEEP),肺复张容积测定,等压法,呼吸模式：BIPAP条件：Ph 20 cmH2O， PEEP分别为0 、5 、 10、15 cmH2O，Ti 6S测定：延长呼气时间，测定ZEEP呼出气量。在不同PEEP时吸气末撤掉PEEP，延长呼气时间，测定呼气量,肺复张容积测定,等压法,肺复张容积测定,P-V曲线法与等压法的比较,肺复张容积测定,肺复张容积测定P-V曲线法,等压法虽然简单，但准确性较差 不能代替P-V曲线法目前肺复张容积的测定仍宜采用 P-V曲线法,肺复张容积测定,CT method,膈顶上1cm CT层面PEEP与ZEEP比较Gattinoni L. Am J Respir CCM, 1995, 151: 1807全肺扫描区别过度膨胀，膨胀，部分复张和塌陷区 Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,肺复张容积测定,CT法-Gattinoni,肺复张容积测定,原理CT空气=0Hu，CT水=1000 HuCT值=500Hu，肺组织50%空气+50%水ARDS塌陷肺CT值100Hu100Hu，塌陷肺泡复张 后，100Hu+100Hu内肺组织减少方法ZEEP和PEEP通气呼气末CT扫描膈肌顶上1cm计算CT值在100 Hu 100 Hu范围内体素结果之差,Gattinoni L. Am J Respir CCM, 1995, 151: 1807,原理 充气不良区(100Hu500Hu)、正常充气区(500Hu 900Hu)、无充气区(100Hu+100Hu)和过度充气区(900Hu1000Hu)。肺泡复张，充气不良和正常充气肺区体积增加 方法 ZEEP和PEEP呼气末螺旋CT，根据层面厚度计算不同CT值肺体积，肺复张后充气不良与正常充气肺组织体积增加值,肺复张容积测定,CT法- Rouby,Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,Gattinonis vs Roubys CT法比较,肺复张容积测定,CT methods: Rouby vs Gattinoni,Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,肺复张容积测定,内容提要,ARDS病理生理ARDS肺复张容积测定P-V曲线法等压法CT法：Gattinonis vs RoubysARDS肺复张测定应用明确肺不张的分布与特点评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用指导PEEP选择,ARDS肺不张的影响因素-附加静水压,Hydrostatic pressure = (1 CT/-1000) Height Maximum sternovertebral dimention of human thorax: 20cmH2OPEEP 20cmH2O不能使ARDS患者肺泡完全复张动物ARDS,Mean Airway pressure 25 cm H2O,ARDS肺复张应用,ARDS下肺气体含量明显降低,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,CT section lcated 5 cm below the carina No differences were observed in the percentage of lower lobes located beneath the heart in two groups,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺不张的影响因素-heart lung interdependence,ARDS肺复张应用,Cardiac mass and volume in ARDS,Cardiac mass was increased by 27% vs NS Mechanism of cardiac mass:Edema of cardiac wallRV dilation secondary to pul hypertensionHyperkinetic state related to SIRS,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,心脏下肺叶气体量明显降低ARDS 73% vs NS 21%,Closed bar: Fraction of gas in lower lobes located beneath the heartOpen bar: lower lobes located outside the heart,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,塌陷肺泡的分布,Local: Loss of aeration predominating in lower lobesDiffuse: Equal loss of aeration to the upper and lower lobes,ARDS肺复张应用,Lung morphology pattern,Local DiffuseLIPNoYesNormally aerated 5512% 24 12%Poorly aerated 23 8% 40 12%Distribution modal BimodalUnimodalPeak of CT distr-727Hu/27Hu7HuCompltot57 546 11,Vieira SRR. AJRCCM, 1999, 159: 1612,ARDS肺复张应用,Diffuse distribution,ARDS肺复张应用,ARDS肺复张应用,local distribution,内容提要,ARDS病理生理ARDS肺复张容积测定P-V曲线法等压法CT法：Gattinonis vs RoubysARDS肺复张测定应用明确肺不张的分布与特点评价VT和SI or Sigh对肺复张的影响 评价PEEP维持肺复张的作用指导PEEP选择,SI前后绵羊复张容积的变化,*,*,与SI前相比，*P 0.05,ARDS肺复张应用,SI有效组绵羊肺气体交换变化,*,*,与SI前相比，*P 0.05,ARDS肺复张应用,潮气量对肺复张的影响,A:PEEP=0, B:PEEP=Pflex, C:at the end of inspiration,D:PEEP=Pflex as in C during expiration,Pelosi P, Goldner M, Mckibben A, et al. Am J Respir Crit Care Med, 2001, 164, 131-140,ARDS肺复张应用,小潮气量通气的局限性,Cretti S, Mascheroni D, Caironi P, et al. Am J Respir Crit Care Med, 2001, 164, 131-140,ARDS肺复张应用,Mean Airway pressure 5 cm H2O,CT Scan :ARDS pig model 30 kg,Optimized Lung Volume Strategy,ARDS肺复张应用,Mean Airway pressure 25 cm H2O,CT Scan :ARDS pig model 30 kg,Optimized Lung Volume Strategy,ARDS肺复张应用,Mean Airway Pressure 40 cm H2O,CT Scan :ARDS pig model 30 kg,Optimized Lung Volume Strategy,ARDS肺复张应用,不同VT的肺复张容积,*,*#,与6ml/kg组相比，*P 0.05;与10 ml/kg相比， #P 0.05,ARDS肺复张应用,内容提要,ARDS病理生理ARDS肺复张容积测定P-V曲线法等压法CT法：Gattinonis vs RoubysARDS肺复张测定应用明确肺不张的分布与特点评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用指导PEEP选择,PEEP效应的影响因素-附加静水压与心脏的影响,ARDS肺复张应用,Rothen H. et al. Br J Anaesth 1993:71:788-795,Re-expansion of atelectasis during general anaethesia,A: CT scan at level of right disphragm B: CT scan 5cm above right diaphragm,ARDS肺复张应用,PEEP诱导recruitment的分布,Puybasset L. ICM, 2000, 26:1215c,In lower lobes: Alv recruitment (ml) = 0.16 X End-expir lung volume(ml) 24ml,ARDS肺复张应用,PEEP导致overdistention的分布,Volume of overdistension(ml)=0.42Parenchyma-900;-800(ml)18ml,Puybasset L. ICM, 2000, 26:1215c,ARDS肺复张应用,PEEP效应的影响因素-塌陷肺泡的分布范围,塌陷肺泡的范围Efficiency of PEEP-induced alv recruitment highly correlated with the proportion of poorly and nonaerated lung parenchyma in ZEEP,Puybasset L. ICM, 2000,26:1215,ARDS肺复张应用,Diffuse: Equal loss of aeration to the upper and lower lobes,Vieira SRR. AJRCCM, 1999, 159: 1612,ARDS肺复张应用,Local: Loss of aeration predominating in lower lobes,Vieira SRR. AJRCCM, 1999, 159: 1612,ARDS肺复张应用,Effect of PEEP on recruitment and overdistention,Puybasset L. ICM, 2000, 26:1215,ARDS肺复张应用,PEEP效应的影响因素-LIP的影响,ARDS肺复张应用,绵羊有无LIP组PEEP复张容积,ARDS肺复张应用,有无LIP患者的复张容积,*,*#,*,*#,与PEEP5 cmH2O相比，*P 0.05与PEEP 10 cmH2O相比，#P 0.05与LIP组比较，P 400mmHg，每15-20min降低PEEP，至PaO2较前一次降低5%, PEEP水平为前一次PEEP结果：PaO2+PaCO2从178.476.5mmHg升至487.8 139.1mmHg，维持肺复张PEEP水平为224cmH2O,V.N.Okamoto et al. Unpublished data, 2003,ARDS肺复张应用,氧分压导向性PEEP选择,V.N.Okamoto et al. Unpublished data, 2003,ARDS肺复张应用,氧分压导向性PEEP选择,对象：47例早期ARDS患者，VCV，VT=8ml/kg， PEEP=10cm/H2O，RR20次/分，I：E=1：1分组与方法： ARM+PEEP组：ARM实施方法为逐步增加PEEP至15、 20、25、30cm/H2O(extended sigh)， 结束后PEEP设为15cm/H2O ARM组：ARM后PEEP仍为10cm/H2O PEEP组：基础通气模式,Lim CM, Jung H, Koh Y, et al. Crit Care Med, 2003,31:411-418,ARDS肺复张应用,氧分压导向性PEEP选择,Lim CM, Jung H, Koh Y, et al. Crit Care Med, 2003,31:411-418,ARDS肺复张应用,氧分压导向性PEEP选择,Lim CM, Jung H, Koh Y, et al. Crit Care Med, 2003,31:411-418,ARDS肺复张应用,氧分压导向性PEEP选择,Lim CM, Jung H, Koh Y, et al. Crit Care Med, 2003,31:411-418,ARDS肺复张应用,氧分压导向性PEEP选择,DO2导向性PEEP选择,ARDS传统的通气策略-经验性PEEP缺点：缺乏科学依据ARDS肺保护性通气策略-最佳PEEP优点：获得最大的DO2，同时考虑PEEP 对循环和呼吸的影响，LIP+2cmH2O 为最佳PEEP,ARDS肺复张应用,邱海波, 郭凤梅, 周韶霞等. 中华内科杂志, 2001, 9,PEEP不足大量肺泡难以复张,LIP：塌陷肺泡开始复张压力，不是全部塌陷肺泡复张压力,ARDS肺复张应用,LIPStart of recruitment,Recruitment occurs along the entire PV curve, even beyond UIP,Gattinoni L. AJRCCM, 2001, 164: 131,ARDS肺复张应用,PEEP and Survoval,A post hoc analysis, 53 patients,Barbas CSV, Medeiros DM, Magaldi RB, et al. Am J Respir Crit Care Med, 200